Despite the availability and convenience of electronic media, the promise of the “paperless” office has not yet come to pass. It is still true, for example, that almost all important documents are printed at least once during their life because paper is still the most convenient medium for reading, annotating and sharing documents. However, once the electronic document is printed almost all “meta” information (such as the version number, last date of modification, date of printing, change history, comments, authors, reviewer's ratings, etc.) is lost unless such information is explicitly printed on the document.
If a user wishes to copy a paper document, then the paper document must be photocopied, or the electronic version must be obtained and a new physical document generated. Copying a paper document generally results in a lower quality copy than would be obtained by printing a new version of the electronic document. However, no record of the copying is retained on either physical document. If a user wishes to modify a paper document, modifications can be written directly on the paper document or the electronic version can be obtained, modifications made and a new version printed out.
Written comments on a paper document cannot be processed automatically using current optical character recognition (OCR) technology. For these reasons, most users choose to retrieve the electronic document. However, this may not be possible, because the electronic copy may no longer exist. If the electronic copy exists, it may not be accessible. For example, the electronic copy may be located behind a corporate firewall or on a storage device (such as a floppy disk) that is not network accessible. If the device is network accessible, the network may be so busy that downloading the document takes a prohibitive amount of time, or the person wishing to obtain it might not have a network connection at all.
Even if the meta information is printed on the document it may be intrusive (in the case of a long change history) and it will normally not be machine readable. Various technologies have been developed for the purpose of storing meta information with a paper document. These technologies essentially are a way to place the meta information or metadata as machine readable code on the paper document and include barcodes, DataGlyphs and magnetic strips. Bar codes are well known and a large infrastructure of readers exits. However, bar code storage density is so low that storing anything more than the document identifier would be impractical. DataGlyphs are essentially high-density, two dimensional codes that can store up to 1000 bytes per square inch. However, with current printing technology, DataGlyphs are visible to the user. While DataGlyphs can store enough information to represent an entire document, the resulting size of the DataGlyph requires a large amount of the paper document be devoted to the DataGlyph, which many users may find intrusive. Magnetic strip technology has been around for many years and is relatively inexpensive. However, it too suffers from low storage density (only on the order of 100 bytes can be stored on the magnetic strip of a bank card, for example). In addition magnetic strips are relatively fragile and can be damaged by contact with other magnetic strips or magnetic material. If a document with a magnetic strip is photocopied, the information in the magnetic strip is not duplicated. Even if the meta information is machine readable it is certainly not modifiable on the physical document.
Various other solutions have been developed to overcome the limitations of printed machine readable code. For example, radio frequency (RF) tags have been associated with objects and are used, for example, for tracking of items in commerce. Copending, coassigned U.S. patent application Ser. No. 09/404,734 filed Sep. 24, 1999, “N-space Indexing of Digital Data Representations Using Physical Tags” describes a small version of an RF tag, called a “smart staple” which is attached to a paper document. The smart staple includes an electronic ID stored in the staple for interfacing with an electronic information system. Copending, coassigned U.S. patent application Ser. No. 09/276,085 filed Sep. 25, 1999, “Marking Medium Area with Encoded Identifier for Producing Action Through Network” describes a system for interacting with paper and retrieving an electronic copy of written notes (by tracking a user's pen as it moves over a paper document). Many Personal Digital Assistants and or palmtop computers enable tracking of handwritten notes, but such systems require access to bulky computing equipment or a network connection.
It would be beneficial to combine the advantages of electronic media with the convenience of paper. It would be beneficial to be able to quickly retrieve the electronic version of a document and all associated meta information in any situation where the paper document is available. It would also be beneficial to be able to store comments about a paper document and modifications to the document in such a way that they could be retrieved and processed electronically, without having to access expensive computer equipment or a network.